Sniffle is from frequentative of sniff (sniff + -le), of imitative origin, mimicking the sound of drawing air audibly through the nose. The historical chain includes Middle English sniff. Morphologically, sniffle is best read as compound, suffixal formation, and imitative formation, yielding an English verb and noun shaped by both form history and later usage. In current English it functions as a verb and noun, with the sense "to draw air audibly through the nose, as when crying or sick". English derivatives include sniffles, sniffler, and sniffly; related forms include sniff and snuffle. The result is an English verb and noun whose etymology preserves the older forms while supporting the word's specialized modern meaning.